I've had mine for a couple of months now and covered about 3000 miles, I'm really happy with it...great value for money! Mine doesn't fit quite as well as in M.C.'s photo as one of the pipes is a bit wonky when cold, but it's a very minor gripe...I'm the only one who notices it.
Performance wise, it's so much freer revving than with the stock zorst making power delivery smoother and more enjoyable imo.